It is known to make electrical connections in air which are insulated by large-dimension screens of insulating material. Such connections are degraded by condensation.
It is also possible to embed the electrical link in an insulating material. This method needs implementing on site which gives rise to a particularly high cost price for this type of link. In addition, the link cannot be dismantled easily.
Furthermore, two types of connection are used for linking electricity substations. There are so-called "oil" connections and so-called "elastomer" connections.
The first type of connection is described, for example, in French patent document FR-2 069 931 which relates to electrical linking devices between at least two contacts under tension in various compartments of an electricity substation. Those high tension electrical link devices enable portions under tension belonging to various compartments to be decoupled. Each compartment includes a cup containing a liquid dielectric and the bottom of the cup is provided with a pluggable contact connected to the conductor. An upsidedown U-shaped busbar of conductor material interconnects two contacts. The emerging portion of the busbar is covered in insulation.
Such connections are relatively bulky and also give rise to problems of sealing.
French patent document FR-2 295 599 describes an elastomer type connection. More precisely, the junction described in that patent is intended for electrically interconnecting portions of sets of busbars or for connecting cable in an electricity substation. The conductors are coated in solid insulation such as epoxy resin. Electrical connections therebetween are surrounded by a metal deflector. An elastomer sleeve is to be found around the connection and the insulation, and is compressed by metal shells which are assembled together by bolts or the equivalent. These shells form conical fields at the two ends of the deflectors, which fields connect with the metal plated surfaces of the insulation.
Such connections also present problems of implementation. They are not easy to dismantle and they cannot be tested on site.